The most common and most likely answer to this crossword clue is the 9 letter word UNDERPLOT
I've seen this crossword clue in The Guardian
U
N
D
E
R
P
L
O
T
Buddy explains!
The straight part
We know that "trick/trick" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case trick/trick = underplot.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does UNDERPLOT mean?
UNDERPLOT noun- A subplot; a plot that is not the main plot of a story.
- A secret scheme or trick.